The Tbird is no Rocket, but it's competent. Weighs everybit as much though, so the torque brings it up to speed a bit more sedately, but still gets you up there smartly. The main difference between a Sportster and a Tbird, is going to be the weight, though the Sportster might be more zippy, the Tbird will have more Interstate manners, once you get used to the weight. Also, Tbirds handle fine for what they are but they are going to be somewhat more ponderous than a Sportster til you get used to it. The Tbird might be geared lower than a Rocket to make the most of the 1700's torque curve, and it might seem more busy at speed. But it's still a very good highway cruiser.